<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style type="text/css">
    @keyframes mymovie {
      0% {
        width: 100px;
      }

      20% {
        width: 200px;
      }

      40% {
        width: 300px;
      }

      60% {
        width: 400px;
      }

      80% {
        width: 500px;
      }

      100% {
        width: 600px;
      }
    }

    div {
      height: 50px;
      width: 100px;
      padding: 10px;
      margin: 10px;
      border: 1px solid #F00;
      animation-name: mymovie;
      animation-duration: 10s;
    }

    #test1 {
      background: url(img/BG06.gif);
      animation-timing-function: ease;
    }

    #test2 {
      background: url(img/BG07.gif);
      animation-timing-function: linear;
    }

    #test3 {
      background: url(img/BG08.gif);
      animation-timing-function: ease-in;
    }
    #test4 {
      background: url(img/BG09.gif);
      animation-timing-function: ease-out;

    }

    body {
      margin: 0;
    }
  </style>
</head>

<body>
  <div id="test1">放大的div块</div>
  <div id="test2">放大的div块</div>
  <div id="test3">放大的div块</div>
  <div id="test4">放大的div块</div>
</body>

</html>